{	var currentComp = app.project.activeItem;	var selectedLayers = currentComp.selectedLayers;	//Create a new null layer	var markerNull = currentComp.layers.addNull();	markerNull.name = "Marker Null";	//Add marker to every in point of the selected layers	//to the null layer.	function addMarker(t, l)	{		markerNull.property("Marker").setValueAtTime(t, new MarkerValue(""));	}	//Main Loop	app.beginUndoGroup("Add Marker Null");	for(var i=0; i<selectedLayers.length; i++)	{		addMarker(selectedLayers[i].inPoint, selectedLayers[i]);	}	app.endUndoGroup();}